The bottling industry is faced with many problems in the control and maintenance of their bottling facilities and procedures; but specific problems or concern herein are problems related to the "contamination" of the bottled products. The term "contamination" is used herein as meaning that any substance other than the intended "non-contaminants" (for example, the pure product and non-contaminating cleansers) is being, has been or will be introduced into the bottle or other container distributed to the consumer. A look at two, typical bottling procedures will help identify more clearly some example problems.
A first procedure which gives rise to concern about contamination is the actual bottle filling procedure. Probably more than a few bottlers have experienced the wasting of many hundreds of gallons of product because a container was filled with improper product. For example, some bottlers will, in the course of a day, utilize the same conveyor and piping systems to fill bottles or cans of two, three or more products. The system will first be used, for example, to fill product 1 containers, then product 2, then product 3, and so on. For example, some beer manufacturers have procedures of utilizing the same conveyor and piping system to ultimately fill containers of premium beers, non-premium beers, and low calorie ("light") beers. If the wrong product is introduced into a particular container, then that product is "contaminated". This is one type of contamination problem. Such contamination can occur either by operator error, in which the operator simply directs product from the wrong storage tank into the piping system, or when there is "residue" from a prior product run remaining in the piping system.
A second procedure which gives rise to concern about contamination is the "refilling" procedure. This is a procedure in which the bottler collects used bottles, refills and reuses these bottles to contain fresh products. Usually these containers were used by consumers to simply dispense of the original product and were then returned to a collection facility. However, the consumer may have used the container to hold a substance other than the original product and then delivered the container at some later time to the collection center. A bottler must be concerned about whether an incoming container has been used to hold any substance which would affect the quality (i.e. taste or smell) of it's product. This potential for contamination of "refillable" bottles is of particular concern when refilling plastic bottles. The concern of refilling plastic, refillable bottles is the possibility that contaminants have been absorbed into the walls of the bottles and then leach into fresh liquid product subsequently placed in the refillable bottles. Because of the absorption and leaching problem, a bottler would rather identify a plastic bottle that has been used to hold a contaminated foreign substance and discard that bottle, rather than attempt to clean and reuse that bottle.
For many years, the industry has sought to address the contamination problem mentioned above. With respect to the first bottle filling procedure mentioned above, some bottlers may have dealt with the contamination problem by, on the one hand, simply accepting the fact of human error and throwing away mis-filled containers; and on the other hand, utilizing excessive amounts of pure product or water to "flush" the pipeline of prior fluids. In this "flushing" technique, a great deal of waste results because the bottler is not positive of the point at which the system has been purged of prior fluids and, thus, purges excessive amount of pure product in order to be certain of clean lines.
In addressing the contamination of refillable plastic bottles, the industry has tested several techniques in the laboratory which have varying degrees of success or failure.